Use of adenosine deaminase as a diagnostic tool for tuberculous pleurisy.

BACKGROUND: A statistical audit of adenosine deaminase (ADA) in pleural effusions was undertaken. METHODS: ADA analysis, cytological and microbiological examinations, and differential cell counts were performed on 462 pleural fluid samples. RESULTS: ADA activity in tuberculous effusions was higher than in any other diagnostic group. At a level of 50 U/l the sensitivity and specificity for the identification of tuberculosis was 90% and 89%, respectively. CONCLUSIONS: ADA activity remains a useful test in the evaluation of pleural effusions.